This invention relates to lasers and more particularly to lasers utilizing the radiation generated from certain exothermic, pyrotechnic reactions to directly pump the laser rod.
There are many applications requiring low-cost lasers including applications requiring expendable lasers. Many of these requirements are related to military applications. These requirements demand low-cost, simple, compact, and lightweight packages with the further requirement of some minimum operating time. One of the biggest problem areas in providing such lasers is the source for pumping the laser rod. Most lasers are pumped by flashlamps which require large batteries and capacitors for energy storage. This limits greatly the degree to which the size and cost of such lasers can be minimized.
In addressing this problem, it has been proposed that the lasers be pumped with a pyrotechnic charge such as compressed pellets and powders of aluminum, zirconium, and the like mixed with an oxygen supplying medium such as KCIO.sub.4. These techniques have not satisfied the problem for a number of reasons. One of the principal is that these reactions generate large quantities of smoke and gas which interfere with the optical pumping. Another problem is that the burning rate of these mixtures is very fast and difficult to control, and thus, laser operation has been achieved only for a few milliseconds. Binders have been employed to control the reaction rates. Binders, however, further add to the smoke and soot contamination of the reaction. A further problem is that the flame front associated with such pyrotechnic reactions extends well beyond the surface of the emitter rendering efficient imaging of the radiation virtually impossible using a compact reflector. Flashbulbs have also been used to pump lasers; however, the laser emission is also of very short duration. In order to increase the burning time, multiple sources (compressed pellets) have been fired in series. However, this method has not met with much success because of contamination problems, etc. This type of pump also requires a large reflector.